OF ACUTE INTESTINAL OBSTRUCTION BY

Acute intestinal obstruction is a common and serious_ surg' ^ nearly 7,000 cases, x932) reported a mortality of 26 per cent in a co ec e ^ mortality has been ncluding 322 cases from Bristol Royal Infirma y. figure although it is in educedlAhis series to ,6 per cent, ^^?0 (.953). -d ? teeping with a recently reported series by Smith, y , ortai,ty could dso the figure quoted in British Surgical Practice (1948)'hls mSn


The Royal Infirmary, Bristol
Acute intestinal obstruction is a common and serious_ surg' ^ nearly 7,000 cases, x932) reported a mortality of 26 per cent in a co ec e ^ mortality has been ncluding 322 cases from Bristol Royal Infirma y. figure although it is in educedlAhis series to ,6 per cent, ^^?0 (.953 33 circulatory rCMUrrec* within 24 hours of operation, and all were due to peripheral occurred in comparison the deaths from strangulated inguinal hernia early and late cases (see Fig. 2), and the cause of death was different: only i patient died of peripheral circulatory failure shortly after operation, (this wa ,|the youngest death, a man of 45 who had been vomiting severely for 5 fays, and1 m gross electrolyte imbalance on admission); the other deaths were a in j and were mainly due to associated cardiorespiratory complications, an , later in the post-operative period: one patient died of heart failure, 10 a c vascular accident and 3 of pulmonary embolus; the other deaths were more ire y due to the obstruction, for 1 inhaled vomit whilst still in the casualty eP^r ?en > (inan of 90 had total gangrene of the whole small bowel, and 1 died o a ea ing su j line following a resection.  Resection was required in 25 cases of strangulated femoral hernia. Twelve of ^c had been strangulated for over 3 days, one for 26 days, and 3 of these died; the ft" a with a shorter history all survived. Three cases requiring a resection had a histof less than 12 hours; one of these was a Maydl's hernia with the strangulated loop| within the abdomen. Only 9 cases of inguinal hernia needed a resection and 2 <> There were 2 cases of reduction-en-masse of an inguinal hernia, the patient in' cases reducing the hernia himself. Femoral hernia seems to carry a lower mortality than strangulated inguinal M in spite of the older average age, higher resection rate, and longer average history, j reason for this would seem to lie in the difficulty of reducing and repairing an 0 large inguinal hernia in an elderly patient with associated cardio-respiratory dise These patients had often been refused elective surgery for their hernia because of1: poor general condition. In comparison the femoral hernia is usually small and j relatively easy to relieve the strangulation. About half these cases were approac from below the inguinal ligament, thus no muscles were cut and an easy convales^ ensured. Strangulated ventral and umbilical hernia had a very high mortality, for there ^ 7 deaths in 27 cases (25 per cent). Five cases required resection and three of 1)1 died. This very high mortality rate was in part due to the attempted repair ofv large herniae, for 2 cases died within 24 hours of operation with gross respir^ insufficiency, and 1 case died of a burst abdomen on the seventh post-operative These patients were often very obese and several were diabetic; these factors v important contributory causes of death.

OBSTRUCTION WITHOUT MENTION OF STRANGULATION
There were 65 cases of small bowel obstruction without strangulation, and 13 ., died (20 per cent). The commonest cause of obstruction in this group was adhes>? there were 40 such cases. The adhesions were all multiple and often very extefl5' most followed previous operations. Other causes were metastases, 7 cases; appei> citis (either retro-ileal or with a pelvic abscess), 6 cases; gall stone ileus, 4 cases; si^1 stricture, 2 cases; carcinoma, 3 cases; simple tumour, Crohn's disease, Mec> diverticulum, 1 case each. Two of the deaths were due to multiple metas^* Appendicitis, gall-stone ileus and carcinoma of the jejunum caused 1 death each, remaining 8 deaths were all due to multiple adhesions.
These cases of so-called ''simple" obstruction frequently had an insidious often with previous minor attacks of colic and vomiting. Many had several days hi?l by the time they reached hospital (see Fig. 3). Only 9 cases had a history of less 24 hours and a third had a history longer than 5 days. As a result many were i" dehydrated?sometimes severely so?by the time they reached hospital, and treat111, for several hours with intravenous fluids was necessary before they were conside fit for surgery.
The diagnosis of established intestinal obstruction was fairly obvious by the 1 these patients reached hospital, although the cause of the obstruction was not ( clear. Many of these cases had plain supine and erect X-rays of the abdomen takejj? admission, these showed various degrees of intestinal dilatation associated with ^ levels and confirmed the diagnosis of obstruction in nearly every case. However ? were of little value in demonstrating the cause of obstruction or the present strangulation.
Difficult operations to relieve these obstructions were sometimes necessary, espeCl, in those cases with extensive adhesions. Two cases had such dense adhesions tb J was considered only possible to do an enterostomy between dilated and collapsed Three cases developed further obstruction post-operatively and required a sec. | , operation. The lateness of these cases, together with the sometimes forming operations in the presence of gross intestinal dilatation, account for the high mof^ Afew0fth treated by gastric suction and intravenous fluids for several as those oneraf0^ U er delay and the impression is that these cases did not do so well e on as soon as their fluid balance had been restored.
Section ^r?jP ,^at^ the lowest mortality of all, there were 65 cases and 7 required re-Cardiar' (Vi ere were onlY 2 deaths (3 per cent). One patient died of congestive as a dis^1 U-rC ?n seventh post-operative day, and the other case was misdiagnose Con\monpC*tlng aneurysm and the strangulation was only found post-mortem. Ine cause of strangulation was a band, often single, this was found 46 times.  Other causes were?internal hernia 9 cases, intussusception 9 cases, volvulus c small gut 2 cases, Meckel's diverticulum 1 case.
The initial severe pain brought these patients to hospital much earlier than' without strangulation. Fig. 3 illustrates this point; the great majority of cases admitted within 24 hours and many within a few hours of the onset of the nine cases there was considerable delay in diagnosis after the patient was s?( hospital, the most common provisional diagnosis was renal colic. One case ^ diagnosed for five days before laparotony showed the true state of affairs, and & thought to be a dissecting aneurysm until post-mortem examination showed a small bowel strangulated by a simple band. The severe pain is commonly refe^ the back, probably due to involvement of the mesentery, and it is all too & interpret this as renal pain. Cases with a tight strangulation may only vomit once' early stages and often the bowel acts after the onset of the pain. The early signs are minimal, there is no distension, little rigidity, and sometimes very, tenderness. This lack of physical signs in the abdomen together with a negative; examination lead to the difficulty in diagnosis when these cases are first seen. , Plain X-rays of the abdomen were taken in 30 of these cases. No evidence ?J struction was reported in 6, paralytic ileus in 2, subacute or partial obstruction and complete obstruction was only reported in 13 cases or just under half. The nej> findings were all in early cases, for in these the small bowel has not had time to o1,, and the colon and rectum still frequently contain gas. Whilst fluid levels and & loops are characteristic of a small gut obstruction that has been present for 24 a relative absence of gas is often the most important sign of an early Strang^ Plate XVIII shows a plain film of the abdomen 2 hours after the onset of pain, tjj an almost complete absence of gas in the small bowel, gas is present in the colon and is a suggestion of a soft tissue mass. At laparotomy several feet of small bo\ve'( found tightly snared by a band, the bowel above the obstruction being quite emP, Major small bowel strangulation rapidly produces shock, from loss of blo? plasma into the bowel lumen, the bowel wall, and the peritoneum. In the later casP must be replaced as rapidly as possible prior to operation. Occasionally cases when the shock develops very early, is often profound within an hour or two, sponds poorly to adequate blood and plasma transfusions, until the strangul^1 relieved. In these cases it is best to operate almost as soon as an efficient plastf3 is running for dramatic improvement was particularly well seen in the two e%tfe ill cases of complete small bowel volvulus, where the blood pressure returned to A as soon as the volvulus was untwisted.

POST-OPERATIVE OBSTRUCTION
There were 25 cases of intestinal obstruction developing after operation, * the patient was still in hospital. This is a serious complication for 6 (25 per cet these patients died. These cases are divided into 2 groups, the first arising wi^ hours of the primary operation, the second after a period of well being, usuallyi the seventh post-operative day. Some of these cases were due to internal hernia or volvulus, and they had ^ abdominal pain. Others were the result of organizing adhesions and followed a of post-operative ileus, one condition gradually merging into the other. It was latter cases that most difficulty was experienced in deciding the right time to re-oP^ In the early post-operative group there were 8 cases, two of these were not reco? and died 48 hours and 9 days post-operatively. In both cases at post-mortem ous bowel due to a small bowel volvulus was found. The other cases were all tjj | by gastric suction and intravenous fluids for a variable time, usually for severe (1 case for as long as 14 days) before it was decided to re-operate. ^ In the later group there were 17 cases and 4 of these died. Four cases de^j sudden severe colic and vomiting; this led to almost immediate laparotomy ^ did very well. The remaining cases developed more insidiously and were tre3 PLATE XVIII strangulation ?Ti abdomen of a young man with a two hour history of internal I iete is an almost total absence of gas, yet at operation 4 feet of strangu-\ lated small bowel was found.
A supine X-ray of the abdomen of a young ma"n^xet at operation 4 feet ?f strangi ~ strangulation. There is an almost total absence oj b >j lated small bowel was found.
rst u PerationaKtriC suct*on-This treatment was continued for periods up to 14 days; le others d'6*1 ^>e.ca^ne Operative. Four of these died, one was not operated on and ?st-one S t-24 hours of the second operation. Fig. 4 shows all the cases of y gastri^ 1Ve.?kstructi?n arranged in columns according to the length of treatment he avera SU,Ctl0n before the second operation, the height of each column representing reas ren^e staY the hospital after the second operation and the shaded ^crease t-^le ^eaths? It is clearly shown that the morbidity and mortality 1 n delay in relieving the obstruction. relieved by simple measures and then have had an elective operation with a l2( prognosis. Carcinoma of the colon was the commonest cause. There were 32r( cases, 19 of these being situated in the sigmoid, 10 in the transverse, and 3 in the colon. There were 6 cases of volvulus, 2 of diverticulitis, and 1 each of carcifl01^. the bladder, simple stricture and stricture of a colostomy. In addition there C cases who both died with gross abdominal distension and faecal impaction folq? the prolonged use of morphia. .a: Many of these patients were elderly and had other serious concomitant o'sc several of the elderly refused treatment when that meant a colostomy. Many L carcinoma cases were very ill on admission with anaemia and dehydration frofl1 j, standing obstruction. Fifteen (50 per cent) of the obstructions due to carcinoid,' one death followed a later resection but all the others died as a direct result of struction, complicated often by associated cardio-respiratory disease, or metast^ A few of the early cases of neoplastic obstruction were treated by primary resea but most by laparotomy and the establishnemt of a colostomy. It would see% even this is too large a procedure in the very poor risk case and a blind caeco* might be used more often. This could be followed by a more satisfactory col?5 c or a resection as soon as the patient is fit.
(i Sigmoin volvulus in 1 case required resection and this patient survived. Tw?,t cases died, one as the result of a further volvulus and the other who was very^ admission was treated by rectal decompression but died shortly afterwards. The t 4 cases were all treated by laparotomy, untwisting the volvulus and the passagel rectal tube. 1

VASCULAR CAUSES OF OBSTRUCTION
This is an uncommon but important cause of obstruction because of the ^ factory methods of treatment and the poor prognosis. There were only 8 cases of these died. According to the Registrar General's Report (1955) this is an incf s cause of death, the crude death rate per million having increased fourfold between and 1955. Three patients had mesenteric emboli and three mesenteric arterial t bosis; these cases were all explored and infarction of all the bowel supplied W superior mesenteric artery was found. None of these cases had the vessel e*P and they all died shortly after the operation. ^ In the early stages after mesenteric embolus there are very few signs to be in the abdomen and the patient remains surprisingly well for several hour5-, diagnosis is therefore difficult, but should be considered in any patient with aUr fibrillation who has an attack of severe abdominal pain. Early diagnosis shop1 t to exploration of the superior mesenteric artery for successful embolectonnieS now been reported (Shaw and Rutledge, 1957). ? The 2 cases that survived were probably cases of mesenteric venous thro111, as both had a previous history of venous thrombosis in other veins. These 2 cas^;! treated by intravenous heparin and antibiotics, and if the non-operative diag^ venous thrombosis could be made with confidence then this is probably method of treatment.

CONCLUSIONS
A consecutive series of 440 cases of acute small and large bowel obstruct1^ been presented. Seventy-one (15-5 per cent) cases died, some of severe asS j disease, but many as a direct result of the obstruction. The factor still chiefly re ible for the high mortality is delay in diagnosis. J The mortality rate has improved from 26 per cent given by Vick for the *1 1925-1930, but the improvement is not in proportion throughout the serie8'^ prognosis has improved most in the cases of internal strangulation, for the rate has improved from 34 per cent in 1932 to 4 per cent in this series. Strang ^ femoral hernia has also shown a marked improvement from 16 per cent to 6 Pe